Potential Probiotic Lactobacillus plantarum P1201 to Produce Soy-yogurt with Enhanced Antioxidant Activity

Abstract

In this study, we evaluated changes in physicochemical properties, total phenol and isoflavone contents, and antioxidant activity during soymilk fermentation by a potential probiotic Lactobacillus plantarum P1201. The P1201 strain showed survival rates of 58.14% and 62.22% after 4 h exposure to acid and artificial gastric acid conditions (pH 2.5), respectively. The optimal conditions for soy-yogurt fermentation by L. plantarum were determined to be as follows: temperature of 35 o C, seed volume of 5.0%, and sucrose content of 10.0%. The total phenol and isoflavone contents and antioxidant activity were higher in soy-powder milk (SPM) yogurt than soymilk yogurt. In particular, the highest levels of isoflavone-aglycones, such as daidzein, glycitein, and genistein (91.50, 12.34, and 61.39 µg/g, respectively), were observed after 48 h of SPM fermentation. Thus, these results suggest that the soy-yogurt extract could be used as a potential source of natural antioxidants in food. Each isolated strains was tested in triplicate for its tolerance in acidified and artificial gastric acidified MRS broth. Means with different lowercase letters (a, b, and c) indicate significant differences of incubation times by Tukey's multiple range test (p<0.05). 항산화 활성이 증진된 두유-요구르트 559후 88.52 및 59.57%의 생존율을 나타내었고 P1201 균주는 92.56 및 62.22%의 생존율을 나타내어 S48 균주보다 우수한 것으로 나 타났다( Table 1) Table 2). 정확한 균주 동정을 위하여 16S rRNA 염기서열 분석을 수행 하였다. P1201 균주의 염기서열을 결정하여 phylogenetic tree 분 석 결과 L. plantarum WCFS1 (AL935263)와 99.0%로 가장 유사 성이 높았다 (Fig. 1). 형태학적, 생리학적, 세포 지방산 조성, 생화 학적 및 분자유전학적 특성을 비교 검토하여 최종적으로 L. plantarum P1201로 명명하였다. 두유 요구르트 발효 중 이화학적 특성 변화배양온도 ( Table 3. Changes of pH, acidity and viable cell numbers during soy milk (SM) and soy powder milk (SPM) fermentations

Changes in phytoestrogen contents and antioxidant activities during fermentation of soybean-powder milks prepared from different soybean cultivars by Lactobacillus plantarum P1201

“…It is important to note that the pH ranges found in the current study are consistent with the pH ranges found in the commercial yoghurt and with soy-yoghurt that was fermented with L. plantarum P1201 (Hwang et al, 2014). The L. plantarum P1201 used in this study exhibited different levels of β-glucosidase activity in 미생물학회지 제52권 제2호 SPMs during their growth under optimal conditions.…”

“…A potential probiotic Lactobacillus plantarum P1201 that was previously isolated from a fermented beverage of plant extract was used as the starter organism for the fermentation (Hwang et al, 2014). Twelve authentic isoflavones were purchased as previously described by Lee et al (2013) Glacial acetic acid, Folin-Ciocalteu phenol reagent, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt (ABTS), potassium persulfate, ferric chloride, sodium acetate, and 2,4,6-tripyridyl-s-triazine (TPTZ) were purchased from Sigma-Aldrich Chemical Co.…”

“…The pH values of the fermented SPM samples were measured using a pH meter (MP 200), while titratable acidity was determined by titration with a 0.01 N NaOH solution and expressed as lactic acid (%) according to the methods previously described by Hwang et al (2014) and Lee et al (2013). The β-glucosidase 204 • Hwang et al…”

“…The antioxidant activity of the SPM extracts was measured by ABTS and DPPH radical-scavenging activity and the FRAP (ferric reducing antioxidant power) assay according to the methods previously described by Hwang et al (2014) and Lee et al (2013).…”

“…In previous study, we reported that Lactobacillus plantarum P1201 showed 58.14% and 62.22% survival rates after exposing 4 h at acid and gastric acid conditions (pH 2.5) (Hwang et al, 2014). In addition, the bioconversion of the isoflavone of Neulchan soybean milk and soybean powder milk by the potential probiotic L. plantarum P1201 resulted in the enhanced levels of total phenolic content and antioxidant activities during fermentation (Hwang et al, 2014). Therefore, L. plantarum P1201 fermentation may serve as a useful tool to develop soybean powder milk as a probiotic dietary adjunct.…”